Varma Manthena V S, Vourvahis Manoli
Pharmacokinetics, Dynamics and Metabolism, Pfizer R&D, Pfizer Inc, Groton, Connecticut, USA.
Clinical Pharmacology, Pfizer R&D, Pfizer Inc, New York, New York, USA.
Clin Pharmacol Ther. 2025 May;117(5):1175-1178. doi: 10.1002/cpt.3564. Epub 2025 Jan 14.
Rifampicin is a widely employed index inhibitor to assess the impact of organic anion transporting polypeptide 1B (OATP1B) inhibition on investigational drugs. The observation of nitrosamines in certain drug products, including rifampicin, has impacted the conduct of clinical drug-drug interaction (DDI) studies with rifampicin drug products. Cyclosporine is a recommended alternative to assess in vivo OATP1B activity; however, challenges exist in its use due to pharmacokinetic (PK) variability and non-selective inhibition of other drug disposition mechanisms.
